Photographic silver halide light-sensitive color element containing 1,3,4-thiadiazoles

ABSTRACT

BY INCORPORATING IN A SILVER HALIDE LIGHT-SENSITIVE EMULSION LAYER CONTAINING A COUPLER OF A PHOTOGRAPHIC LIGHTSENSITIVE COLOR FILM THE COMPOUND REPRESENTED BY THE FORMULAE   5-(R-S-)-1,3,4-THIADIAZOLE-2-THIOL OR   5-((5-(HS-)-1,3,4-THIADIAZOL-2-YL)-S-(CH2)N-S-)-1,3,4-   THIADIAZOLE-2-THIOL   WHEREIN R IS AN ALKYL GROUP OR AN ARALKYL GROUP AND N IS AN INTEGER OF 2 THROUGH 10, A DYE IMAGE HAVING IMPROVED GRANULARITY CAN BE FORMED BY PROCESSING THE COLOR FILM WITH A DEVELOPER CONTAINING A P-PHENYLENEDIAMINE DERIVATIVE.

Patented Jan. 12, 1971 U.S. Cl. 96-100 Claims ABSTRACT OF THE DISCLOSURE By incorporating in a silver halide light-sensitive emulsion layer containing a coupler of a photographic lightsensitivecolor film the compound represented by the formulae HS-l wherein R is an alkyl group or an aralkyl group and n is an integer of 2 through 10, a dye image having improved granularity can be formed by processing the color film with a developer containing a p-phenylenediamine derivative.

BACKGROUND OF THE INVENTION (1) Field of the invention The present invention relates to a photographic lightsensitive color element having a light-sensitive emulsion layer containing a silver halide and a coupler. In particular, it relates to such photographic light-sensitive color elements wherein a specific compound is incorporated in the emulsion layer. The term emulsion layer in this specification includes a light-sensitive emulsion layer, an intermediate layer, a protective layer, and other emulsion layers. The incorporation of the compound permits the formation of a dye image having improved granularity when said color element is processed with a developer containing a p-phenylenediamine derivative.

(2) Description of prior art A photographic silver halide light-sensitive color element of a type wherein couplers are incorporated in the light-sensitive emulsion layers of the element is generally composed of a support, a red-sensitive silver halide emulsion layer containing a cyan color forming coupler, a green-sensitive silver halide emulsion layer containing a magenta color forming coupler, and a blue-sensitive silver halide emulsion layer containing a yellow color forming coupler.

In general, a photographic light-sensitive color material for camera use is usuall prepared by applying to a support, such as, a cellulose ester or a polyester, the redsensitive layer, the green-sensitive layer, a yellow filter layer, and the blue-sensitive layer, in this order.

Furthermore, a photographic light-sensitive color material for print use is generally prepared by applying to a support, such as, paper, a cellulose ester or a polyester, the above-mentioned light-sensitive emulsion layers, in the same order as above, or by applying to the support the blue-sensitive layer, the green-sensitive layer, and the redsensitive layer, or the blue-sensitive layer, the green-sensitive layer, and the red-sensitive layer in this order. These layer arrangements and other variations thereof may be regarded as an important factor.

Various improvements have been attempted to obtain a dye image having good photographic properties in the case of forming a dye image by processing the photographic light-sensitive color element, having the aforesaid composition, with a developer containing a p-phenylenediamine derivative. For example, as the improvements in regard to light-sensitive elements, one has been proposed wherein a combination of an emulsion having comparatively coarse silver halide grains and high speed, and an emulsion having fine silver halide grains and low speed is employed as the silver halide emulsion layer, each having light sensitivity. In another proposed improvement, a combination of a colorless coupler and a colored coupler, or a compound capable of forming a colorless reaction product by the reaction thereof with a developer, is incorporated in an emulsion layer as a coupler.

An object of this invention is to provide a photographic light-sensitive color element capable of forming a dye image having good photographic properties. Another object of this invention is to provide a photographic lightsensitive color element capable of forming a dye image in which the granularity of the image has been fined without lowering thespeed.

SUMMARY OF THE INVENTION These objects of this invention can be achieved according to the present invention by incorporation, in an emulsion layer of a photographic light-sensitive color element, including at least one light-sensitive emulsion layer containing at least a silver halide and a coupler, at least one of the compounds represented by the general formulae:

wherein R is an alkyl group or an aralkyl group and n is an integer of from 2 through 10, inclusive.

That is, by using the photographic color element of this invention as mentioned above, the graininess of the dye image thus formed can be improved without lowering the speed of the light-sensitive element, regardless of the above-mentioned layer arrangement, couplers and other factors.

DETAILED DESCRIPTION OF THE INVENTION The compounds used in this invention and represented by the above general formulae are illustrated as follows, although the invention is not limited to them:

These compounds may be incorporated in a photographic light-sensitive element by adding them to emulsions during the manufacturing process or before coating together with general additives for coatings. However, the inventors have confirmed experimentally that the addition of the aforesaid compounds to emulsions during the manufacturing process, especially at the emulsificating stage, is most effective for improving the graininess of the dye image without lowering the speed of the light-sensitive color element. In the case of adding the compounds to the emulsions before coating, it sometimes happens that the speed of the light-sensitive color element thus formed is reduced although the graininess is improved. On the other hand, when the compounds are incorporated in the emulsions during the manufacturing process, the speed of the light-sensitive element thus prepared is scarcely reduced, while the graininess of the dye image is effectively improved as in other cases. It is at the emulsificating stage of the emulsion manufacturing process that it is most effective to incorporate the compounds to produce finer graininess without lowering the emulsion speed. By manufacturing process and emulsiticating stage are meant the following: photographic silver-halide emulsions are usually manufactured by the steps of (1) preparation of the raw material, (2) emulsification, (3) the first or physical ripening, and (4) the second or chemical ripening. The manufacturing process includes all of the aforesaid steps while the emulsificating stage is step (2).

The optimum condition for the elfective addition of the aforesaid compound must be determined by the kind of compound and the emulsion to be employed, but in the case of adding the compound to the emulsion during the manufacturing process or before coating, the effective range of the addition amount thereof is from 10- to mols per one mol of silver.

In general, if the addition amount is less than that of the above value, the effect of improving the graininess of the dye image is not obtained, and, if larger than that value, the compound has a bad influence on photographic properties, i.e., it reduces the speed and the soft tone of the dye image, which makes the addition impractical.

The graininess of a dye image formed by processing a photographic light-sensitive color element containing the aforesaid compound of this invention with a developer provides a dye image better than that formed by any conventional method wherein the aforesaid compound of this invention is not incorporated in an emulsion layer of the photographic light-sensitive color element. That is, the same effect is observed in cases 1) Where the coupler is oil soluble or a coupler is soluble in water or an alkali, (2) the light-sensitive color element is composed of a single light-sensitive emulsion layer or multiple silverhalide emulsion layers, and 3) the light-sensitive emulsion layer contains an optical sensitizer or does not contain such a sensitizer.

Therefore, upon comparing the case of employing the aforesaid compound with a conventional case wherein such a compound is not employed while assuming the graininess of the dye images is the same in both cases, an emulsion containing coarser silver halide particles can be employed in the invention as compared with the conventional case.

Now, the practice of the present invention will be expluined by reference to the following examples.

4 EXAMPLE 1 This example showed the granularity of a dye image formed and the relative logarithmic speed of a photographic light-sensitive color element in the case of adding Compound I as described above to a high-sensitivity silver iodo-bromide emulsion containing 8.5 g. of the silver halide per 100 g. of the emulsion, 6 mol percent of iodine to the silver and 11 g. of gelatin. The granularity was estimated by G value (E. W. H. Selwyn; Photo. 1.; 75, 571 (1935) and ibid. 79, 513 (1939). 6 value is used for comparing the extent of variation of the density of image grains by a microdensitometer and the smaller the value, the finer are the grains. 3

Thus, into 1,000 g. of the above-mentioned emulsion were added successively the following additives at 40 C.: 20 ml. of 1% by weight of 5-methyl-7-hydroxy-2,3,4- triazaindorizin, and a magenta coupler-containing emulsion having the following composition:

Gelatin (5% solution): 100 g.

Sodium alkylbenzene sulfonate (5 soln.): 8 -ml. Magenta coupler: 10 g.

Acetone: 10 ml.

Dibutylphthalate: 15 g.

They were stirred for 30 minutes in a mixer.

The magenta coupler used is one shown by the following formula and was added to the emulsion so that the proportion of the magenta coupler was mol per one mol of silver.

The emulsion thus prepared was applied to an undercoated cellulose acetate support in a dry thickness of 4.5 :05 microns.

After exposure, the photographic film was subject to the following procedures:

(1) Color development for 8 minutes at 20 C. Composition of developer:

Diethylphenylenediamine sulfate: 2.75 g. Hydroxylamine sulfate: 1.2 g. Sodium sulfite (anhydrous): 2 g. 'Potassium bromide: 2 g. Sodium carbonate: g. Water to make 1,000 ml. (2) Hardening for 8 minutes. Composition of hardening solution:

Glaubers salt: 150 g. Water to make 1,000 ml. (3) First fixing for 5 minutes. Composition of fixing solution:

Hypo: 150 g. Water to make 1,000 ml. (4) Water washing for 5 minutes. (5) Bleaching for 5 minutes. Composition of bleaching solution: Potassium ferricyanide: g. Water to make 1,000 ml. (6) Water washing for 5 minutes. (7) Second fixing for 5 minutes (same as first fixing solution). (8) Water washing for 20 minutes.

Selwyns G-value of the density of image thus obtained about 13:10 and the relative logarithmic speed (=D=fog +0.2) are shown in the following table.

Test No.

M01 of additive I AEXMOI X103 v 1 2 Asmfm 0 +0. ()1 +0.02 +0.01 +0.04 +0.02 G(D-1.0) 5. 7 5. 0 5. 2 4. 7 4. 2 4. 0

As shown in the above table, it will be understood that the granularity was made finer by the addition of the additive Without lowering the speed, as compared with the control example wherein the compound was not added.

EXAMPLE 2 Into the emuslion of Example 1 there was added 0.42 mol/1 mol-Ag of the orthocromatic sensitizing dye having the following structure:

CzHs C2 Thereafter, Compound II was added to the emulsion and the resulting emulsion was applied to a film support. The film was exposed and subjected to the procedures as in Example '1, the results of which are shown in the following table:

Test No.

Mel-additive 3 1 1 Agxmol X v 0 A A 1 2 4 Asozuo 0 0 0.01 0.03 0.05 0.06 own) 4.4 a 4.2 3.9 3.6 2.8 2.6

The granularity was compared, as in Example 1, in the case of adding Compound III to a silver chlorobromide emulsion containing 6.0 g. of the silver halide per 100 g. of emulsion, 80 mol percent of silver bromide to silver, and 7 g. of gelatin. The results are shown in the following table:

It will be understood that the granularity became finer as the amount of additive was increased.

EXAMPLE 4 Using the emulsion of Example 1 with the addition of 10- mol of each of Compounds 1V, V and VI per one mol of the silver halide, the same procedure as in Example 1 was repeated. The granularity of the dye image thus obtained was measured and the G-value at a density of 1.0 was compared as a percentage of the G-value in the case wherein the above compounds were not added. Also, the difference in speed by a usual sensitometer was compared by the logarithmic value. The results are shown in the following table, from which it will be understood that by the addition of Compound IV, V or VI, the granularity was refined without lowering the speed.

Compound III was added to a silver iodo-bromide emulsion containing 9.5 g. of the silver halide per g. of emulsion, 5 mol percent of silver iodide to silver, and 6.3 g. of gelatin. The granularity and speed were measured while varying the amount of the additive.

That is, to 1,000 g. of the above emulsion were added successively the following additives: 20 ml. of 1% by Weight of 5-methyl-7-hydroxy 2,3,-4-triazaindrizin, and a cyan-coupler-containing emulsion having the following composition:

Gelatin (5% solution): 100 g.

Sodium alkylbenzenesulfonate (5% soln.): 8 ml. Cyan coupler: 10 g.

Dibutyl phthalate: 1 5 g.

The cyan coupler has the following structure and was added so that the proportion thereof was /30 mol per one mol of silver:

The mixture was stirred for 30 minutes in a mixer.

The resulting emulsion was applied to a cellulose acetate support by a usual manner in a dry thickness of 5 microns.

The same procedure as in Example 1 was repeated for the photographic film thus prepared and Selwyns G- value about 1.0 of the image density thus obtained and the relative logarithmic speed (D==fog+0.2) were measured. The results are shown in the following table.

By the addition of 5 l0 mol based on silver, the granularity could be refined without lowering the speed.

EXAMPLE 6 The emulsion of Example 5, but containing no compound of this invention (Emulsion A), was prepared by increasing the ripening temperature to 50 C. Also, an emulsion containing 0.1 g. of Compound II per 100 g. of silver nitrate (Emulsion B) was prepared. After preparing photographic films by using the thus prepared emulsions and processing them as in Example 5, the granularity of the cyan dye images and the speed of the films were measured. The granularity of the cyan dye image obtained by using Emulsion A was completely the same as that of the cyan image obtained by using Emulsion B, but the relative speed 8 in the case of using Emulsion B to that of the case of using Emulsion A was +0.23. That is, when the compound of this invention was added to the emulsion, the speed was markedly increased as compared with the case of adding no composition of this invention Where the graininess was the same.

What is claimed is:

1. A photographic light-sensitive color element comprising a support and at least one silver halide light-sensitive coupler-containing emulsion layer or a layer adjacent the emulsion layer, said layer having incorporated therein a compound selected from the group consisting of compounds represented by the formulae:

II II IIS-C C-SCIIs 3. The photographic light-sensitive color element as claimed in claim 1, wherein said compound is Its-( (ii-SCHzQ 4. The photographic light-sensitive color element image as claimed in claim 1, wherein said compound is T? IISC CS(CH)9CII;

5. The photographic light-sensitive color element image as claimed in claim 1, wherein said compound is NN ll ll lIS-C 8 6. The photographic light-sensitive color element claimed in claim 1, wherein said compound is ii i i i Hs-o CS(OHQ)4SC C-SH 7. The photographic light-sensitive color element claimed in claim 1, wherein said compound is II II U II HSC C-S(CH2)1oS- CSII 8. The photographic light-sensitive color element as claimed in claim 1, wherein the addition amount of said compound is from 10- to 10 mols per one mol of silver.

9. The photographic light-sensitive color element as claimed in claim 1, wherein said layer is a silver-halide light-sensitive emulsion layer containing a coupler and said compound has been incorporated in said layer by adding the compound to the emulsion during the manufacturing process thereof.

10. The photographic light-sensitive color element as claimed in claim 1, wherein said layer is a silver-halide light-sensitive emulsion layer containing a coupler and said compound has been incorporated in said layer by adding the compound to the emulsion during the emulsificating stage thereof.

J. TRAVIS BROWN, Primary Examiner US. Cl. X.R. 9655, 74 

